Water heater



NOV. 6, 1934. Q W OTT ET AL Re. 19,363

WATER -HEATER original Filed Jan. 2S. 1951 Reissued Nov. 6, 1934 UNITEDl STATES PATENT UFFICI?.

WATER HEATER Oran W.

Ott, Los Angeles, and Arthur J.

Smithers, Alhambra, Calif., assignors to Pacific Pipe & Supply Company, Los Angeles, Calif., a corporation of California This invention relates to water heaters and particularly to domestic water heaters. In localities where the Water contains lime compounds there is considerable difficulty in operating heaters, particularly heaters of the coil type because of the deposit of sulphate or carbonate of lime on the interior of the coil. This deposit or scale materially interferes with the eiciency of the heater in transferring heat to the service Water being heated and also materially reduces the effective cross section lof the coil, thereby diminishing the amount of water that can flow through the heating coil for delivery at the point where the hot Water is to be used. It has been found that the deposits from hard water are greatly increased with the temperature of the plate or surface that is heating the water. In other words, a considerable deposit occurs where a flame or hot gases are located on one side of the heating wall and the water being heated is incontact with the other side of the heating wall.

It has been attempted to overcome these dii-Iiculties by constructing a heater'with trapped water which comes in contact with the wall that is highly heated by the fire and this trapped water is utilized as a transfer medium for transferring the heat to the service water. In this way the deposit of lime or similar compounds in the service water chamber is greatly reduced. However, if the trapped water is completely confined it may develop a considerable pressure and this would necessitate a substantial increase in the thickness of the plates conning the trapped water. Furthermore, if the construction is such as to permit substantial replacement of the trapped water by the service water during the continued operation of vthe heater, the depositingy of scale will not be prevented. l

'Ihe general object of this invention is to provide a heater of simple construction whichwill overcome these difliculties and which is particularly adapted for heating hard waters; also to provide a heater of this type which will be highly efficient in operation and which is so constructed as to maintain equilibrium between the pressure of the trapped water and the service water chamber in which the service water is being heated but without creating a condition that would cause any substantial replacement of the trapped Water by the service-water.

In other words, water is substantially trapped and is substantially free from replacement by the service water. In this way the deposits in the trapping chamber are greatly reduced.

A further object of the invention is to provide 12v claims. (01.122-1'1) a heater which can be constructed at a low cost which will be eicient in transferring heat to the service water but in which the deposits from the `hard water will be reduced to a minimum.

Figure 2 is a horizontal section taken about on the line 2--2 of Figure 1. Y

Referring more particularly to the parts, in constructing the heater we provide a shell 1 preferably of cylindrical form in an upright position, the lower end of the said shell being utilized to form a fire-box 2 provided with means for developing heat, for example, a gas burner 3. The upper side of the fire box 2 is nearly closed by a fire-box head 4, with a central opening carrying a fiue 5 preferablyl of vtubular form that vextends upwardly and passes through the upper head 6 ofthe shell 1. Over the fire box head 4 is a water head 7 which is formedwith a central opening carrying a tubular `jacket 8 that surrounds the ue 5 and cooperates with the same to form an annular relatively narrow water jacket 9 communicating with the water space 10 that is formed between the heads 4 and 7. Theheads 4 and 7 are preferably made vof sheet metal and crowned in an upward direction so that their conf veX sides are disposed upwardly. They are formed with flanges 11 that may be Welded to the inner side of the shell 1.

The tubular jacket 8 extends up to anr elevated point in the tankor shell 1 and is preferably secured to an annular head or collar 12 secured to the iiue just below the. head 6. Preferably at an elevated point so as to be remote from the ebullition point in the heater we provide means of communication betweenl the water jacket space or compartment 9 and the service Water space 13 that is formed within the shell 1 and around the jacket 8. This may be accomplished in any suitable manner but we preferl to employ for this purpose, an opening 14 formed in the jacket just below the jacket head 12, that is to say at a point that is remote from the re box and the ebullition zone at the lire-box (see Fig. l) This opening should not be so large as to permit circulation between the trapped water space and the space 13. We'prefertoprovide the ue rw'ith means forincreasing-the temperature and transfer of heat at as low a point in the heater as possible. For this purpose we prefer to provide the interior of the flue 5 with a plurality of balies 15 which may be of general fan shape (see Figure 2) and carried on a common `located between the nue and the service water compartment. Tt is lalso 'evident "that, as the kcoirn'nu-nicat'ioii ventbejtweefn the two Water Achambers is 'lofcated remote from 'the `iire-box and the zone, there wiil'be very slight agitation of the trapped Water in the vicinity 'of the vent, and-a A'relaitfi'v'ely snail Aopening will suice -to re- {lieve the pressure 1d-ue to expansion without occasicning'any substantial replacement of `trapped water by service water.

operati@ of lthis heater it will Abe evi- {that although the opening Y-14 prevents any 'possibility developing -a higher pressure in the trap compartment 9 than in the service water compartment l 3 nevertheless, fthe water in the tipd vwater compartment "is substantially trapped, that is ^to say, #the construction iis lsuch as to prevent free circulation between `'the trapped -Water and service compartment.

O f course, if boiling occurs in the trapped water Ithereis .a tendency 'for a slight lemission of water to occur at l'the -fepening 14 into Athe upper part 'ofthe cit-ramper 1 3, lbut AAin this operation the bemes llcooperae -to corinne -the lhighest temperature tea low ylevel in the fiiue. 1n this way `het water rising in the acket space 9 tends'to have -its temperature reduced before lit reaches the opening 14. I-f any slight emission of water Ydoes occur from'the jacket spaces, Ya replacement of this water lwould occur but such replacements are in such smal-l quantities that vthey do not substantially increase the deposit of lime jcomf pounds in the jtrapped Waiter space. The head t(i is provided with nipples l20 and-'251, one of which would be an inlet and the other anfoutlet'for the heatedservice water.

'What We claim is:

`1. lIn -a Waterheater of the kind described, the combination of a s hell Ahaving a service water A'c h'ainlzrerfor the service Water to be heated, a Water inlet and awater outlet gtherefor a firebox with a head in the lower part of the shell, ahot gas flue extending ,up from 'the said head for 'carrying up gases of `combustion vfrom the fire box, a Water headgmounted in the shell above the hre-box head and cooperating with the fire-box head and lthe shell y'to form a trapped water compartment over the fire-box head, atubularjacket Ysurrounding the Y said `ilue and connected to the water head soas 'to form a trapped water jacket around the flue communicating with the s aid water compartment, a cover head secured to the said shell, and 'means V'located remote frein the ebullitipn dpoint adjacent .Sad refhexghead, f9.1'

maintaining pressure communication between the water jacket and the service water space within the said shell and operating to maintain equilibrium of pressures without circulation of Water between the trapped water in thejac-ketand the service water being heated Ain the water space of .the shell, said pressure communicating means being the sole means of communication between `the water jacket and the service water compart- 2. In a water heater of the kind described, the

.combination of a shell having a service water chamber forfthe service water to be heated, a water inlet "and ,a ,water outlet therefor, a fire box with a nre-Iboxhead in the lower part of the shell, a lnot gas flue extending-up from the said iforfcarrying gases of combustion from the nre-box, a lwater head mounted in the shell above the nre-box 1head and cooperating with there-ibex head and the shell to form a trapped ,water compartment over the lire-box head, a tubular jacketsurrounding the said ,flue and connected to the water head so as "to form a trapped Water jacket around theiiue communicating with the s a-id water 'wmpartment 'a 'cover head secured to the said shell a restricted opening remote from the ebullition `point at said nre-box head and adjacent fthe upper endpf the `tubular i?let and operating `to maintain equilibrium 'of pressure without circulation between the water inthe jacket `andthe water space lof the shell, said pressure communicating vmeans being "the sole means of communication `between the water jacket and -the service water compartment.

3. jIn a water heater Vof the Ykind described, the combination 'of a lshell having ja service water chamber for the 4service `water Jto be heated, a lwater inletan-d -a Water outlet therefor, a fire-*box with areeboxiheadin the'lower-part ofthe shell,

for carrying up gases of Acomjdust`ion frdm the fire-box, a water head `rno'u'r'itec'l in theshell above the reebox 'jhead and cooperating with vthe ,tiren begr lhead and `the shell to form fa trapped water compartment 4over the rebox head, la tubular Vjacket surrounding Y the said "ilue and connected to the Water head so as to form v`a *trapped water ack'et around the flue communicating with the said water compartment, a cover J'head secured "to `-the said shell, :and lmeans located remote from i the bullition point of 'said firehbox head, for maintaining pressure equalization between the water j acke't and fthe service water space Within the said' shell and operating L to maintain equilibrinm iotf pressure without-circulation vbetween f `the trapped water in the jacket vand the `service Ywater vvbeing heated in jthe 'water space ,of 'the shell, said pressure communicating `means "being the sc le means of communication lbetween jthe water iacketand 'the vservice water compartment,

said heater head and said water head being of crowned form Vwith the convex side Adisposed upwar'dly end havingflanges at their edges secured to said shell.

` "4. In a-wa'terheater of Vtlrkind described, "the surrounding the lsaid ,flue and connected gto the icc water head so as to form a trapped water jacket around the flue communicating with the said water compartment, a cover head secured to the said shell, and means located at a high level within the shell for maintaining communication between the water jacket and the service water space within the said shell and operating to maintain equilibrium of pressures between the trapped water in the jacket and the service water being heated in the water space of the shell, said heater head and said water head being of crowned form with the convex side disposed upwardly and having flanges at their edges secured to said shell, and baiiles carried within the iiue for checking the outward ow of the gases of combustion, thereby increasing the temperature toward the lower part of the flue and jacket, and reducingr the temperature of the trapped water in the upper part of the jacket.

5. In a water heater of the kind described, the combination of a shell having a service water chamber for the service water to be heated, a water inlet and a water outlet therefor, a head in the lower part of the shell, a flue extending up from the head for carrying up a heating gas, a water head mounted in the shell above the rst named head and cooperating with the first named head and the shell to form a trapped water compartment over the first named head, a tubular jacket surrounding the said flue and connected to the water head so as to form a trapped water jacket around the flue communicating with the said water compartment, a cover head secured to the said shell and means located on the jacket for maintaining pressure communication between the water jacket and the service water space within the shell and operating to maintain equilibrium of pressures without circulation of water between the trapped water in the jacket and the service water being heated in the water compartment of the shell, said pressure communicating means being the sole means of communication between the water jacket and the service water compartment.

6. In a water heater of the kind described, the combination of a vertically elongated shell having a service water compartment therein, an open inlet maintaining a constant supply of service water to the service compartment, an, outlet connected with the service compartment only, a firebox at the lower end of the shell, a flue having its central axis at the axis of said shell, said heater having an annular wall and other walls cooperating with the annular wall and the flue to form a trapped water compartment with trapped water therein located between the flue and said service compartment, and means of communication between the water compartments located at a high level remote from the lire-box and the ebullition zone of the heater, operating to maintain pressure communication between the water compartments, said compartments being completely full during operation, said communication means being of relatively small area, said parts cooperating to heat the service water by the trapped water, and said communication means cooperating with the other parts of the heater to prevent substantial replacement of the trapped water by the service water during the operation of the heater, said communication means being the sole means of communication between said compartments.

'7. In a water heater of the kind described, the combination of a vertically elongated shell having a service water compartment therein, an open inlet maintaining a constant supply of service water to the service compartment, an outlet connected with the service compartment only, a firebox at the lower end of the shell, a nue having its central axis at the axis of said shell, said heater f having walls including an annular wall cooperating with the flue and shell to form a trapped water compartment with trapped water therein located between the flue and said service compartment, and means of communication between the water compartments located at a level remote from the fire-box and the ebullition zone of the heater, operating to maintain pressure communication between the water compartments,

said compartments being completely full during operation, said parts cooperating to heat the eervice water b-y the trapped water, said communication means operating to permit expansion, and cooperating with the other parts of the heater to prevent substantial replacement of the trapped water by service water during the operation oi the heater, said communication means being the sole means of communication between said compartments.

8. In a water heater of the kind described, the combination of a vertically elongated shell having a service water compartment therein, an open inlet maintaining continuous supply of service water to the service compartment, and an outlet connected with the service compartment only, a :e

fire box at the lower end of the shell, a single ue extending up from the ire box, said heater having annular walls cooperating with said flue and shell to form said service Water compartment and an annular trapped water compartment with I trapped water therein located between the ue and said iirst named compartment, and means of communication between the water compartments located at a high level remote from the lire-box and the ebullition zone of the heater, operating ji.

to maintain pressure communication between the water compartments, said compartments being completely full during operation, said communication means being of relatively small area, said parts cooperating to heat the service water by the lf trapped water and said communication means operating to prevent substantial replacement of the trapped water by the service water during the operation of the heater, said communication means being the sole means of communication between said compartments.

9. In a water heater, the combination of an upright cylindrical shell, walls therein including annular walls spaced apart to form a trapped' water compartment and a service water compart- "`s tion at all times between the water in the service compartment and the water in the trapped water compartment and located at a level remote from said heating means, said opening being the only means of communication between said compartments, and operating to maintain equilibrium l "I of pressures between the said compartments without effecting substantial water circulation between the same.

10. In a water heater of the kind described, the combination of a vertically elongated shell having rfr0 a service water compartment therein, an inlet and an outlet connected kwith the vservice compartment only, a lire-box at the lower end ofthe shell, said heater having annular -Walls and fother walls, certain of said walls cooperating with certain of said annular walls to Aform a single flue extending from the fire-box and said walls forming la trapped water compartment vwithtrapped water therein located between the flue -and the -service Water compartment, and means of Icommunication between the water compartments located at a level remote from the fire-box and its adjacent zone of the heater, operating to maintain pressure communication between the water compa-rtments, said compartments being completely full during operation, said parts cooperating to heat the service water by the trappedwater and said communication means cooperating with the -other parts of the heater to prevent substantial replacement of the trapped water by the ser-vice water during the operation of the heater, and -being the sole means of communication between lthe said compartments.

1'1. In a Water heater the combination of an upright cylindrical shell, a fire-box at the lower .end of said shell, a plurality of annular upright walls Within the shell, one of which forms a iue for -carrying gases of combustion upwardly from the re-box and other walls cooperating with the annular walls to form a trapped water compartment for trapped `water heated by the gases in said flue, and cooperating to form a service water compartment adjacent the trapped water compartment, an open inlet maintaining a constant supply of service water to the service compartment, an outlet for delivering service water connected to the service compartment only, both of said compartments being completely full of water at all times during 4the operation of the heater, and means .fof communication maintaining communirases .cation Iat .all times 'between the Water inlthe service compartment and the ywater in -the trapped water compartment and located .at Ia level remote 'from said fire-box, said parts kcooperating to impart heat .from the trapped Water to the service water, while preventing .substantial replacement .of the trapped water fby service water-during the `operation .of the heater. i

12. In a water heater, the combination of an `upright cylindrical shell, la nre-box with a iire- -box head at the lower end `of said shell, a plurality of annular :upright wall .means within the shell, `one of said ,annular vwall means forming a flue for carrying gases of combustion .upwardly from .the 'nre-box, and a water head cooperating 'with other of :the annular `wa'll means to form a trapped water .compartment for trapped `water having walls :heated vlby 'the hot gases within said flue, said water head cooperating withfsaidkshell and one of :said .annular 'wailfl :means to form a yconnected :to the service compartment only, both of said compartments :being completely `full of water at all ktimes during the operation of the heater, and means of communication maintaining communication at all times between .the

water in the service compartment and the water in the trapped water compartment 1ocated at a level remote :from said fire-box, all of said parts cooperating to impart heat from the trapped water to the service water,

but preventing substantial replacement of the j,"

trapped Water by service water during the operation of the heater.

ORAN 'W. OTT.

ARTHUR J. SMITHERS. 

